Tuesday, January 13, 2009

Gibson Deluxe Tuners (a weak design?)

Please note that this post is part one of four posts. I highly recommend reading all four posts in order before acting on any of the information.

The other parts are located here:

Part 2: http://diystrat.blogspot.com/2009/01/gibson-deluxe-tuners-part-two.html
Part 3: http://diystrat.blogspot.com/2009/02/gibson-deluxe-tuners-fix.html
Part 4: http://diystrat.blogspot.com/2010/01/gibson-deluxe-tuners-revisit.html

I have a problem with one of the tuners on my Les Paul. It had the problem already when I bought the guitar a few years ago and I managed to do a temporary fix, but the problem has resurfaced.

Before you continue, please note that this is written from an engineering point of view.

Firstly, let’s have a look at a typical stamped (open-backed) guitar tuner.

There are several components and many names for those components, so my apologies if I use ones that you are not accustomed to. Firstly, the tuner can also be called the tuning head, tuning peg, or the machine head (and possibly other names). It has a main plate, through which the main cylinder (or capstan), passes. The capstan is the shaft that the string itself passes through. On the end of the capstan is a gear, sometimes called the pinion gear, and a screw/bolt holds that on to the end of the capstan. Then we have another shaft or pin with the tuner knob (or button) on the end of it. This pin has a gear on it too (in fact they are one part in most cases), and this particular gear is known as a worm gear. From now on I will just refer to this shaft as the worm gear.

As an aside, and for any non-engineer-minded people out there, the reason a worm gear is used is because turning the button/knob will rotate the worm gear, which will in turn rotate the pinion gear and the capstan, thus tightening or loosening the string, whereas no matter how much you tighten the string, the pinion gear cannot force the worm gear to turn. This is a really good way to keep strings in tune without making it really hard to turn the knob.

OK, back to the description of the tuner. There is one further feature that I have not yet mentioned and that is the retaining “claws” which are part of the main plate and hold the worm gear in place. The claws stop the worm gear from moving away from the pinion gear or falling away from the main plate. The plate stops the worm gear from falling against the guitar and the pinion gear stops it from falling out in the direction of the capstan. So hopefully you can see that the worm gear cannot possibly fall out unless the pinion gear is removed.

Now to the Gibson Deluxe Tuners (and why I think they are a weak design).

As you can see, the tuner has the same components as any standard open-backed tuner, but please note one subtle difference – although the claws stop the worm gear from moving away from, or towards the pinion gear (i.e. from side to side), they don't stop it from falling away from the main plate. Seriously, it can just fall right off.

“But wait!”, I hear you Gibson Deluxe Tuner fans shouting, “The Gibson Deluxe Tuners have a back cover which stops the worm gear from falling away from the main plate!”

Well, you are correct, but this leads me to the problem with my tuner... the back cover has fallen off. And this brings me to my second criticism of Gibson Deluxe Tuner design. You would think that, if the back cover was the only thing holding the worm gear in place, it would be held on in a way that would be very hard to move.
Let’s have a look at their design.

The back cover is held on with two little tabs (one of mine is slightly damaged, but this happened while I was trying to find a solution to keeping it in place. It originally fell off with the tabs intact). Now as an engineer, I would think that a tab should at least fold over to keep something in place, but these ones just go into slots and do not appear to be twisted, folded, or in any other way modified once they go through the slots. In other words they are held in by “interference fit” only, so that they can come out just as easily as they went in (edit: actually, this isn't 100% correct - they are "staked" in place [see the comments at the end of this post], although that doesn't add much strength in the direction they would fall off ). Now let’s think about what’s on the end of the worm gear. That’s right, a big knob/button that sticks out and is basically on the end of a lever. What do we often use levers for? Well, for prising things out of place for one. The longer the lever, the easier it is. So one accidental knock on the tuning knob and you can dislodge the back cover, letting the worm gear fall out of place.

In the course of trying to find a single replacement Gibson Deluxe Tuner (which, not surprisingly, cannot be bought separately), I have noticed many other people scrambling to buy single replacements off ebay or asking if anyone has a spare one on musicians’ forums. A full set is not cheap either; around £60 would not be unusual. I wouldn’t even mind paying that if I though it was a good strong design, but I think you can guess by my rantings how much I think of these things. Unfortunately replacing them with anything other than originals devalues the guitar, so there isn’t much choice.

Additionally, on the front face of the guitar head you need to use a bushing (also called a ferrule) which stops the capstan from rubbing on the wood of the guitar when it is being rotated, and whereas these are normally press-in bushings on tuners of similar design to Gibson Deluxe Tuners, on the actual Gibson ones, they are screw-in bushings. Now I have no complaints about this, design-wise, I’m just saying that there are very few replacements available other than the Gibson Deluxe Tuners.

Gibson Deluxe Tuner bushing (and washer)

Standard bushing

So stay tuned (no pun intended) for the next blog post, where I will try to fix mine.


Anonymous said...

Hey--I have the same problem with a GD tuner on my J-45. Looking forward to see if you can get it fixed in your next post!

Anonymous said...

exactly the same problem with my les paul studio,the back plate has come off one tuner and another is held on by one claw only, again i hope they can be without having to be replaced

The Cave of the Dead said...

I've realised the same thing after a whole long story.

Now I've got a replacement tuner, but I don't know what size push-in bushing fits the deluxe tuner hole. Can't find clear info on this.

stu said...

Hey The Cave of the Dead,

What you need is a "conversion bushing", like the ones for sale here:


Hope that helps.

The Cave of the Dead said...

It helps a lot. I think the previous ones were to convert from Grover holes to vintage tuners. They were slightly too big for the deluxe holes.

But these conversion bushings should do the trick to go from 80's style screw-in bushing deluxe tuners to vintage style push in bushings right?


stu said...

Tell you what.... I happen to have a set of those conversion bushings that I'm going to use for another project. I'll do a sizing test on my Les Paul and get back to you.

stu said...

Hey, The Cave of The Dead. I took one of the tuners off my Les Paul and measured the hole as 10mm. I measured the outer diameter of the conversion bushings and they are JUST over 10mm. The difference was so minimal that I was able to push the bushing in with one finger. It was a nice snug fit. Not loose at all, and not too tight either. Here's a pic of the conversion bushing in place:

The Cave of the Dead said...

Brilliant. Thanks for that. I'm going to order a set of those.

Anonymous said...

Just googled and found this - had exactly the same thing, bought a set of 6 tuners and now I've realse that there are two different hole sizes and I don't know whether I have got the right one (I am currently awaiting some other bits in the post and will only start disassembling when I can do the lot together.)

Anonymous said...

I am about to purchase a set of Grover deluxe waffle backs to fit to my J45 and I will keep the originals in a bag in case I even sell. I'm more interested in how the thing plays and behaves than I am in re-sale value.The machine heads fitted to my J45 historic series are Kluson and they are hopeless. New non Gibson quality tuners will suit me fine.

Deuce2222 said...

I tried to post a comment earlier but it would not let me so I apologize if this duplicates.

The problem is you comment that the cover is only held on by an interferences fit of the two tabs.

That is not correct. You must remove the entire tuner from the headstock. Insert the two tabs and the cover. The tabs are then "staked" on by flipping the tuner over and hitting the tab ends where they come through flush on the reverse side. Stake them with a small chisel or screwdriver. Look closely at the tab ends where they come through and you will see where this was done previously at the factory. (Please look) If you just insert them and hope they will stay on with an "interference fit" you will be disappointed. They will fall back off. They will fall off as they did before, and again-- as gravity is not just a good idea it is a law. If however you do this correctly the cover will stay on if you do not hit them against something hard which should be avoided with an expensive guitar like a Gibson.
All kidding aside let me know if you have any trouble. I do a lot of work on old Gibsons in Florida where Skynyrd was king and this usually works as it is how they are assembled at the factory---one of your tabs appears to be partially broken so I have had to have a jeweler friend braze on a couple occasions--still cheaper than a new set of tuners.

stu said...

Hi Deuce2222,

You are, of course, completely correct. I did post a comment at the end of part 3 regarding the stake trick, but I should really write a new updated post, as I've heard this same thing from several sources since this post was originally written. Thanks for the reminder.


stu said...

OK, the new post is up:

Unknown said...

The new Gibson deluxe tuners are now made with die-cast casings attached to the plate by three tags. If a tuning key gets knocked...:_(
I repair guitars and have seen plenty Fenders etc with vintage style tuners that have bent key shafts from impacts and the casing is still holding on solidly. I have a Gibson SG in the workshop at the mo with one of the tuner casings clean off - not a mark on any part of the tuning key and the shaft is perfectly straight.
Bad design and materials...

Jmoon said...

I had a slightly different problem with one of my machine heads on my 2002 Gibson LP Studio. The capstan of the G string machine head would actually rotate counter-clockwise by maybe a 10th of a turn. Just enough to constantly go out of tune with really any attack whatsoever. I was skeptical about replacing the tuners because of the obvious devaluing...but... the Planet Wave Auto Trim locking tuners in the 3+3 set actually line up with the pre-drilled holes for the GD machine heads. There is only one screw to hold them on, and you can see the second hole where there is no screw, however... they lock, and my LP stays in tune now. Plus they have black capstans, and just look kind of cool against the black headstock.

I of course retained the original tuners for value purposes, but I could literally grasp the capstan with my thumb and index finger and rotate it backward slightly without much twisting pressure. Not going to cut it.

I removed the back of the tuner after reading this post and tried to tighten the screw, and had trouble getting the cover back on. After reading the post about smaking it to set the tabs (mine only has one tab) I will smack it when I get back home, and put it back in the zip-lock bag with the others in case I ever sell the LP, but I don't think I will.

All this to say, the Planet Waves Auto trim set will fit right in, work like a charm, and you don't have to drill holes in your headstock. They were about 60 US$. Worth it, it was like getting a new guitar.

Jmoon said...

One note on the Planet Waves tuners if you are new to them... The auto trim function is neat, but if you make a common mistake, you won't like them. Avoid this:

Many people think you should pull the string taught through the eyelet before tightening... dont. You can wrap the string around the post just like any other tuner. Leave about 2 inches of slack on the string before tightening the lock screw on the bottom. That will lock the string, and you can wrap the excess around the post. It will still trim the string for you.

If you pull the sting taught, lock it, then tighten it, it will give a very loose action, and there aren't enough wraps to function the way it was designed to function. I've never had any problems with these, I have them on my 05 Strat Deluxe, and my 06 Tele deluxe, and now my LP.

Just thought I should post this after reading some comments on reviews of the tuners posted by people who made the above mentioned mistake.

Anonymous said...

One advantage to the flimsy mounting of the winding shaft allows it to easily pop apart if the tuner should strike against something. Easier to manage than sustaining unrepairable damage (and having to buy SIX new tuners). Nice job of explaining the mechanism which all guitarists should learn about before they change their tuners in anger.

Anonymous said...

Someone somewhere incorrectly says he thinks the Gibson Deluxe Tuners are made by Schaller. NO WAY ARE THEY MADE BY SCHALLER. I have Schallers on my ES135 and they are night and day, they look similar, but they're NOT the same.

stu said...

Thanks for your comment. I've edited the post accordingly.

Linzi said...

Agree completely about quality issues. Replaced my Custom Shop ES 339 Gibson branded Klusons with Grovers almost immediately as they would not even keep the guitar in tune. Grovers are fine. My tech warned about the inferior construction of the originals.

Anonymous said...

If your guitar tuners were not defective right from the start they will give you many years of flawless operation. The points you are making are all based on the fact that something was not right therefore it led to more problems down the road. Well, this is true with ANYTHING on the face of this earth that was designed, engineered and manufactured to be and perform a certain way but something in the chain of its components either failed or was tampered with during operation. Long story short, it is not the Deluxe Tuners the problem but they way they were used. If by any chance you received a defective instrument from the get-go, (very unlikely for Gibson) you should have been able to identify it immediately and have it fixed under warranty or get a replacement. Before you blame things on others, first do a self assessment.

stu said...

Hi, Anonymous. Thanks for your comment. I’m always happy to receive them, good or bad. However, I must disagree with you, if you’ll permit. The entire point of this particular blog post was to demonstrate, from an engineering point of view, how the design of these particular tuners is weak and prone to failure. They are not obviously defective from day one, but rather their design weakness becomes apparent after stresses are applied in a particular direction. These are stresses that a tuner should reasonably be able to deal with. It has even occurred to me that Gibson Deluxe Tuners might be designed specifically to fail, rather than transfer any knocks to the peghead, possibly causing a neck break (which, of course, Les Pauls are also susceptible to). Gibson’s quality control, incidentally, is not infallible, as you seem to believe. Just look at the other comments posted above.

Anonymous said...

I had a bent tuner on my Les Paul Classic & took it apart to straighten it in a vice (worked ok).After taking the back cover off I noticed the housing was stamped "Made in Japan" or maybe just "Japan". So are these tuners actually made by Gotoh ?